Classifications

• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08G—MACROMOLECULAR COMPOUNDS OBTAINED OTHERWISE THAN BY REACTIONS ONLY INVOLVING UNSATURATED CARBON-TO-CARBON BONDS
  • C08G81/00—Macromolecular compounds obtained by interreacting polymers in the absence of monomers, e.g. block polymers
  • C08G81/02—Macromolecular compounds obtained by interreacting polymers in the absence of monomers, e.g. block polymers at least one of the polymers being obtained by reactions involving only carbon-to-carbon unsaturated bonds
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08L—COMPOSITIONS OF MACROMOLECULAR COMPOUNDS
  • C08L23/00—Compositions of homopolymers or copolymers of unsaturated aliphatic hydrocarbons having only one carbon-to-carbon double bond; Compositions of derivatives of such polymers
  • C08L23/02—Compositions of homopolymers or copolymers of unsaturated aliphatic hydrocarbons having only one carbon-to-carbon double bond; Compositions of derivatives of such polymers not modified by chemical after-treatment
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08G—MACROMOLECULAR COMPOUNDS OBTAINED OTHERWISE THAN BY REACTIONS ONLY INVOLVING UNSATURATED CARBON-TO-CARBON BONDS
  • C08G81/00—Macromolecular compounds obtained by interreacting polymers in the absence of monomers, e.g. block polymers
  • C08G81/02—Macromolecular compounds obtained by interreacting polymers in the absence of monomers, e.g. block polymers at least one of the polymers being obtained by reactions involving only carbon-to-carbon unsaturated bonds
  • C08G81/024—Block or graft polymers containing sequences of polymers of C08C or C08F and of polymers of C08G
  • C08G81/027—Block or graft polymers containing sequences of polymers of C08C or C08F and of polymers of C08G containing polyester or polycarbonate sequences
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08L—COMPOSITIONS OF MACROMOLECULAR COMPOUNDS
  • C08L67/00—Compositions of polyesters obtained by reactions forming a carboxylic ester link in the main chain; Compositions of derivatives of such polymers
  • C08L67/04—Polyesters derived from hydroxycarboxylic acids, e.g. lactones
• • C—CHEMISTRY; METALLURGY
  • C12—BIOCHEMISTRY; BEER; SPIRITS; WINE; VINEGAR; MICROBIOLOGY; ENZYMOLOGY; MUTATION OR GENETIC ENGINEERING
  • C12P—FERMENTATION OR ENZYME-USING PROCESSES TO SYNTHESISE A DESIRED CHEMICAL COMPOUND OR COMPOSITION OR TO SEPARATE OPTICAL ISOMERS FROM A RACEMIC MIXTURE
  • C12P7/00—Preparation of oxygen-containing organic compounds
  • C12P7/62—Carboxylic acid esters

Definitions

• films which are readily biodegradable as these can be used for example as components of disposable diapers, ostomy bags and even as ordinary wrappings with a reduction in problems of disposal after use.
• Biodegradable polymers comprise hydroxybutyrate groups (PHB polymers) especially those PHB polymers which also comprise hydroxyvalerate groups (PHB/PHV copolymers).
• PHB polymers hydroxybutyrate groups
• PHB/PHV copolymers PHB/PHV copolymers
• Polymers of this type are described in for example our European Patents 52,459 and 69,497. However, although they can be formed into satisfactory films with care, when used alone there is a tendency with such polymers to produce a proportion of off-specification material and the manufacturing process is subject to considerable constraints. It is desirable therefore to devise improved polymer compositions of this type.
• Blends of such polymers with polyolefins possess favourable properties provided that the components are rendered compatible.
• Polypropylene is particularly favourable and has the advantage that it degrades more readily than polyethylene especially if no antioxidants are present. It is however difficult to render these materials compatible with PHB polymers.
• a compatibilising agent which comprises a block copolymer in which in at least one block (Block A) at least half of the mass of the block is represented by alkylene or preferably alkyl side chains, which preferably have straight chains and which are suitably at least five and preferably at most 20, for example six to twelve carbon atoms long, and in which in at least one other block (Block B) at least half and preferably at least 70% of the mass of the block is represented by side chains which comprise hydroxybutyric acid residues and optionally also other hydroxyalkanoate residues which are preferably hydroxyvalerate residues.
• the units of the side chains are hydroxybutyric acid residues and any remaining units of said side chains consist essentially of hydroxyvalerate units.
• These side chains are suitably of average molecular weight 100-80,000 and preferably 200-10,000.
• the mass ratio of Block A to Block B is preferably 1:5 to 5:1.
• This invention comprises said compatibilising agents and also polymer blends compatibilised with them. These agents are believed to be useful as compatibilisers in polyolefin/polyester blends generally.
• Block A may derived from a polymerisable olefinically unsaturated monomer (preferably a methacrylic or acrylic monomer) having a moiety linked to the polymerisable olefinically unsaturated bond which is or includes a hydrocarbyl group of at least 5 carbon atoms (preferably at least 7).
• the alkyl or alkenyl groups of Block A are usually part of a larger grouping such as alkyl (or alkenyl) ester or alkyl (or alkenyl) ether groups, and will be spaced from the polymerisable olefinically unsaturated double bond by an intermediate chemical species; typical spacer groups are ester groups and ether groups.
• the upper limit for the number of carbon atoms in the hydrocarbyl group is not critical but for practical purposes will usually be about 22 (more usually about 15).
• the use of less than 5 carbon atoms in the hydrocarbyl group tends to result in poor compatibilisation.
• the monomer may of course also possess a hydrocarbyl group(s) of less than 5 carbon atoms in addition to the hydrocarbyl group of >5 carbon atoms).
• the olefinically unsaturated monomer is preferably a methacrylic or acrylic monomeric species, the polymerisable unsaturated bond being provided by the double bond of a methacrylic group CH 2 ⁇ C(CH 3 )-- or the double bond of an acrylic group CH 2 ⁇ CH--. More preferably the monomer providing block A is an ester of methacrylic acid or acrylic acid of formula CH 2 ⁇ CR 1 CO 2 R 2 where R 1 is methyl or H and R 2 is an alkyl, cycloaolkyl or aryl group of at least 5 carbon atoms, more preferably at least 7 carbon atoms (usual ranges being 5 to 20 and 7 to 15 carbon atoms).
• Examples of such monomers include n-octyl methacrylate, 2-ethylhexyl methacrylate, n-decyl methacrylate, lauryl methacrylate, cyclohexyl methacrylate, and docosanyl methacrylate (and the corresponding acrylate compounds).
• n-Octyl methacrylate and 2-ethylhexyl methacrylate are particularly preferred.
• the compatibilising agent may comprise a copolymer comprising at least one block of poly alkyl acrylate or poly alkyl methacrylate units (suitably of molecular weight 10,000-200,000 and preferably 20,000-200,000) and at least one block which comprises acrylate or methacrylate units of which a substantial proportion for example 20 to 100% are esterified to hydroxyacid chains as aforesaid.
• the compatibilising agent may be made by reacting a copolymer reactant comprising at least one block which comprises a poly primary alkyl acrylate or methacrylate and at least one block which comprises tertiary alkyl acrylate or methacrylate or acrylic or methacrylic acid units with a polymer comprising hydroxyacid units as aforesaid, for example a PHB polymer.
• a copolymer reactant comprising at least one block which comprises a poly primary alkyl acrylate or methacrylate and at least one block which comprises tertiary alkyl acrylate or methacrylate or acrylic or methacrylic acid units with a polymer comprising hydroxyacid units as aforesaid, for example a PHB polymer.
• a catalyst for example an acid catalyst and optionally in the presence of a solvent.
• an olefin or alcohol corresponding to the tertiary alkyl group is also formed.
• the block containing the tertiary alkyl group acrylate or methacrylate units may also comprise other more stable acrylate or methacrylate ester units for example those of lower alkyl groups for example C to C 3 primary or secondary alkyl groups, if desired.
• the copolymer reactant may be made according to the procedures of our European Patent Application No 434,316 and UK Patent Application 8929024.1 from which the said European Patent Application claims priority the disclosures of which are incorporated herein by reference.
• the polymer blend may be made by contacting the polyolefine, PHB polymer and a copolymer reactant at an elevated temperature sufficient to form the compatibilising agent and to melt the components under mixing conditions, for example at a temperature of 190° C. optionally in an extruding process.
• the polymer blend is preferably conditioned by holding it for at least 10 seconds and suitably 20 seconds to 1 minute at a temperature of 40° to 70° C. after formation at a higher temperature.
• the polyolefin is preferably blended as a high surface area polypropylene powder made by a gas phase process.
• a three necked 500 ml flask, equipped with mechanical stirrer and pressure equalised dropping funnel and a rubber septum is flame dried under vacuum to remove all air and moisture.
• the flask is filled with dry nitrogen and cooled in an ice/salt bath to 0° C. 120 ml toluene (distilled over sodium) is syringed into the flask. While stirring at 0° C. 1.8 ml triisobutyl aluminum solution (molar in toluene) and 0.35 ml of tButyl lithium (1.7 molar in hexane) is syringed into the flask, thus constituting an initiator solution.
• the copolymer is precipitated from its solution in toluene by addition to a solution of 10% by weight HCl in methanol.
• the polymer is filtered off and dried in a vacuum oven at 80° C. for 4 hours.
• the yield of copolymer is 98% of the monomers fed.
• the calculated number average molecular weight is 175000.
• the number average molecular weight determined by gell permeation chromatography (GPC) is 40000.
• the number average (Mn) to mass average (Mw) molecular weight Mn/MW was 1.3.
• Polyoctylmeth-acrylate is known to come out of GPC showing much lower Mn than real Mn. This is because the GPC was calibrated for polymethyl methacrylate only.
• compatibiliser was dissolved in 100 ml of toluene and added to the polypropylene powder. This was stirred for 2 hours to allow the compatibiliser to absorb onto the polypropylene. (The toluene helps by swelling the polypropylene amorphous regions). The toluene is then removed on a rotary evaporator and the polypropylene is dried in a vacuum oven for 2 hours at 80° C. PHB/PHV copolymer powder is added to the polypropylene. All blends were prepared on a total weight of 1 kg after addition of all components. The blends were then extruded into pellets using a single screw extruder at 190° C.
• a compression moulded plaque of composite is drawn to approximately 8 times its original length and width at about 50° C.
• Films were made of a 75% Polypropylene 25% PHB/PHV copolymer by weight composition containing 1% of the compatibiliser. The samples were very easily drawn into films, compared with pure PHB/PHV copolymer.

Applications Claiming Priority (3)

Publications (1)

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Citations (7)

• 1992
  • 1992-02-28 GB GB929204275A patent/GB9204275D0/en active Pending
• 1993
  • 1993-02-26 WO PCT/GB1993/000401 patent/WO1993017064A1/en active IP Right Grant
  • 1993-02-26 DE DE69314778T patent/DE69314778T2/de not_active Expired - Fee Related
  • 1993-02-26 EP EP93904264A patent/EP0629219B1/en not_active Expired - Lifetime
  • 1993-02-26 AU AU35721/93A patent/AU666710B2/en not_active Ceased
  • 1993-02-26 NZ NZ249218A patent/NZ249218A/en unknown
  • 1993-02-26 JP JP5514670A patent/JPH07504449A/ja active Pending
  • 1993-02-26 AT AT93904264T patent/ATE159539T1/de not_active IP Right Cessation
  • 1993-02-26 CA CA002128435A patent/CA2128435A1/en not_active Abandoned
  • 1993-02-26 US US08/295,626 patent/US5478892A/en not_active Expired - Fee Related
• 1994
  • 1994-08-26 NO NO943157A patent/NO943157D0/no unknown
  • 1994-08-26 FI FI943930A patent/FI943930A0/fi unknown
  • 1994-08-26 KR KR1019940702981A patent/KR950700348A/ko not_active IP Right Cessation

Patent Citations (7)

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